A. Technical Field
The present invention relates to a cement dispersant, a method for producing a polycarboxylic acid for a cement dispersant and a cement composition. More specifically, it relates to a cement dispersant synthesized by using a polyalkylene glycol ester type monomer or a polyalkylene glycol-ether type monomer, having alkylene oxide obtained by the addition reaction in a specific temperature range, and a cement dispersant which can achieve high percentage in water reduction, a method for producing a polycarboxylic acid for such a cement dispersant and a cement composition.
B. Background Art
In recent concrete fields, improvement in durability and strength of concrete structures is strongly demanded. Reduction in unit water amount is an important subject, and development of high performance AE water reducing agents is energetically conducted in each cement admixture maker. Of those, polycarboxylic acid type high performance AE water reducing agents have the excellent characteristic which exhibits extremely high water reducing property which cannot be achieved by other high performance AE water reducing agents such as naphthalene type. However, the water reducing performance is not still sufficient.